Methotrexate
What is it?
Methotrexate (Maxtrex®, Metoject®) is used to treat a number of conditions:
Lower doses (25-30mg or less a week) are used in cancer chemotherapy and in the treatment of autoimmune diseases, including Crohn’s disease, rheumatoid arthritis and psoriasis.
High doses (50mg or more) of methotrexate are sometimes given to end an ectopic pregnancy where the pregnancy develops in the fallopian tube instead of in the womb. Higher doses may also be used in cancer chemotherapy.
Benefits
What are the benefits of using methotrexate in pregnancy?
In cases of ectopic pregnancy, treatment with high dose methotrexate can stop women from becoming seriously ill or dying, and decrease the chance of fallopian tube damage that might affect future fertility.
Methotrexate should not otherwise be used in pregnancy.
Risks
What are the risks of using methotrexate in pregnancy?
Methotrexate used in early pregnancy can cause miscarriage and/or serious birth defects in the baby, and can affect the baby’s growth in the womb.
The risk of poor pregnancy outcomes is greater with high doses of methotrexate. However, lower dose methotrexate (used for autoimmune disease) has also been linked to miscarriage, and it is not clear whether it may sometimes cause birth defects. For this reason, methotrexate is not recommended during pregnancy.
After stopping methotrexate, it can stay in the body for some time. The manufacturers of methotrexate recommend that women avoid getting pregnant for six months after finishing treatment with methotrexate.
Women who are taking methotrexate and planning a pregnancy should speak to their doctor to discuss switching to a different medicine before stopping contraception.
Alternatives
Are there any alternatives to taking methotrexate in pregnancy?
Yes, usually. Switching to a different drug may be an option. Some women find that an autoimmune illness improves during pregnancy, and so a doctor may advise that treatment can be altered.
Women on methotrexate who are planning a pregnancy or who become pregnant should arrange to see their doctor or specialist as soon as possible to decide on the best possible treatment during pregnancy.
No treatment
What if I prefer not to take medicines in pregnancy?
Poorly controlled autoimmune disease puts your pregnancy at risk as it can cause miscarriage, preterm delivery and low infant birth weight. To help reduce the chance of these outcomes and to stop an autoimmune disease from flaring, most women will be advised to take some form of medication during pregnancy.
Women receiving chemotherapy may also be advised to continue treatment during pregnancy to prevent a relapse.
A doctor will only prescribe medicines when necessary and will be happy to talk through about any concerns.
Will I or my baby need extra monitoring?
As part of routine antenatal care, most women will be offered a detailed scan at around 20 weeks of pregnancy to check the baby’s development.
For women who have taken methotrexate during the first trimester, or in the month before pregnancy, an extended anomaly scan may be offered with extra focus on the areas commonly affected by methotrexate exposure (mainly the skull and face, fingers and toes, and spine and ribs). It is important to understand that scans are not guaranteed to pick up all birth defects. Extra scans may also be offered to check the baby’s growth.
In general, women with the health problems that methotrexate is used to treat will be more closely monitored during pregnancy to make sure that they remain well.
Are there any risks to my baby if the father has taken methotrexate?
Overall, there is no strong evidence of an increased risk to babies if the father took methotrexate before or around the time of conception. For more information please see the bump leaflet on Paternal methotrexate exposure.
Who can I talk to if I have questions?
If you have any questions regarding the information in this leaflet please discuss them with your health care provider. They can access more detailed medical and scientific information from www.uktis.org.